Small update, just bought another SE/30 today.

Was just a few miles from home, wasn't too expensive either (30 €)

According to the seller, the screen is showing checker flag patterns.

I removed the casing before payment, to be sure that both Roms were present this time... they were, as well as an Asante MacCon ethernet card and a set of 8 ram sticks (1 Mb each)

So i think in the end i didn't paid too much, more to come ... :